1. Technical Field
The present invention relates to sprinkler systems, and more particularly, to adjustable arc of coverage sprinkler nozzles in which spray elevation and flow are also adjustable to provide a water spray precipitation over a settable area of coverage.
2. Related Art
U.S. Pat. Nos. 5,148,990 and 5,588,594 disclose adjustable arc of coverage spray nozzle sprinklers and related prior art. When using such sprinklers as part of an in-ground sprinkler system, it is necessary during setup to adjust the arc of coverage, as well as the stream angle of the nozzle to provide uniform coverage. Also, as noted in U.S. Pat. No. 5,588,594, the disclosure of which is incorporated herein as if fully set forth, it is necessary to adjust the flow rate when changing the stream angle.
Presently, a nozzle having a preset stream angle is required to achieve a desired spray range such as 8 ft., 10 ft., 12 ft., 15 ft. and 17 ft. For nozzles having a fixed arc of coverage, e.g., quarter-circle, half-circle, three-quarter-circle and full circle coverage, separate spray nozzles are required for each range to provide approximately matched precipitation rates for sprinklers operating on the same watering zone with the same run time interval.
Adjustable spray nozzles of the type disclosed in U.S. Pat. No. 5,588,594 are designed specifically to provide matched precipitation for each group of different ranges. This allows use of only one nozzle for each range instead of four for each range.
Nevertheless, to achieve multiple ranges, multiple nozzles are still needed. There are no spray nozzle sprinklers commercially available which provide both adjustable spray angle and arc of coverage. A need clearly exists for a spray nozzle in which the stream elevation angle, and the arc of coverage (as well as the flow rate) are all adjustable, thereby permitting use of one manufactured nozzle configuration rather than between 5 and 15 different spray nozzles which are now required to be carried and available on an irrigation job for a matched precipitation rate system.
Similarly, there are no commercially available spray nozzle sprinklers in which the flow rate automatically adjusts as the spray elevation angle is changed to maintain a substantially constant precipitation rate.
Despite the lack of variable spray elevation angle capability, an adjustable arc sprinkler constructed in accordance with U.S. Pat. No. 5,588,594 has many advantages, but it would also be desirable to be able to provide similar features in a product which has a simpler design, and is less costly to manufacture.